#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
vector<char> cheng(vector<char>& vc, int n)
{
	vector<char> C;
	int pos = 0;
	for (int i = 0; i < vc.size(); i++)
	{
		if (vc[i] == '.') {
			C.push_back('.');
			continue;
		}
		int m = vc[i] - '0';
		m *= n;
		m += pos;
		pos = m / 10;
		C.push_back('0' + (m % 10));
	}
	if (pos) {
		C.push_back('0' + pos);
	}
	return C;
}
int main()
{
	int n;
	string d;
	vector<char> vc;
	cin >> n >> d;
	for (int i = d.size() - 1; i >= 0; i--)
	{
		vc.push_back(d[i]);
	}
	vector<char> v;
	for (int i = 0; i < n; i++)
	{
		v = cheng(vc, 2);
		vc = v;
	}
	bool vis = false;
	int jin = 0;
	for (int i = 0; i < v.size(); i++)
	{
		if (vis) {
			int p = v[i] - '0';
			p += jin;
			if (p == 10) {
				jin = 1;
				v[i] = '0';
			}
			else {
				v[i] = '0' + p;
				jin = 0;
			}
			continue;
		}
		if (v[i] == '.') {
			vis = true;
			continue;
		}
		if (v[i]!='.') {
			int p = v[i] - '0';
			p += jin;
			if (p >= 5) {
				jin = 1;
			}
			else {
				jin = 0;
			}
		}
	}
	if (jin) {
		v.push_back('0' + 1);
	}
	for (int i = v.size() - 1; i >= 0; i--)
	{
		if (v[i] == '.') {
			break;
		}
		cout << v[i] - '0';
	}
	return 0;
}